Hard chrome plated vibrating board of an ultrasonic-wave washer

ABSTRACT

A vibrating board for an ultrasonic-wave washer fitted to an opening formed in the bottom of a washing tank to form a vibrating bottom of said tank with a plurality of tremblers fixed thereto at its under surface of the board which contacts a washing liquid in said tank is plated with a hard chrome. Moreover, at least four corners of the vibrating board are formed thinner than the substantial central area of the board to which the tremblers are attached from the below. Such construction of the vibrating board can avoid an erosion on the board, eliminated a breakdown of the tremblers and ensure a reliable transmission of an ultrasonic-wave to the liquid, and thus prolongs the durable years of the vibrating board.

United States Patent 1 1 1 3,730,439 Morita May 1, 1973 1541 HARD CHROMEPLATED VIBRATING 2,950,839 8/1960 Hahn ..220/64 BOARD OF AN T A W3,058,014 10/1962 Camp..... ....259/DIG. 44 WASHER 3,l98,489 8/1965Finch ..259/DIG. 44 [75] Inventor: Katsumi Morita, Higashikatsushika- Pi E i william I, Pri

gun, Japan I g v Assistant ExaminerPhilip R. Coe [73] Assigneez HakamadaK-inzoku Kogyo Attorney-Shles1nger, Fltzsnnmons & Shlesmger KabushikiKaisha, Edogawa-ku, 57] ABSTRACT Tokyo, Japan 7 A vibrating board for anultrasonic-wave washer fitted [22 1 Filed M 1972 to an opening formed inthe bottom of a-washing tank [21] Appl. N0.: 236,070 to form a vibratingbottom of said tank with a plurality of tremblers fixed thereto at itsunder'surface of the board which contacts a washing liquid in said tankis [52] Cl. ..259/72, 68/3 SS, 134/1, plated with a hard chronm Moreoverat least four 134/ i84, 259/DIG. 44, 310/83, 310/ corners of thevibrating board are formed thinner than [51] Int. Cl. ..B0lf 11/02 v theSubstantial central area of the board to which the [58] Field ofSearch.. ...259/DIG. 44, l R, "emblemare attachgd f the below.

' 310/83, 26 Such construction of the vlbratmg board can avold anerosion on the board, eliminated a breakdown of the tr'emblers andensure a reliable transmission of an ul- [56] Cited trasonic-wave to theliquid, and thus prolongs the UNITED STATES PATENTS durable years' ofthe vibrating board. 2,815,193 12/1957 Brown m ..68/3 ss x I 4 Claims, 4Drawing Figures HARD CHROME PLATED VIBRATING BOARD OF AN ULTRASONIC-WAVEWASHER This invention relates to a vibrating board for anilltrasonic-wave washer, and more particularly man improvement in avibrating board attached to the bottom of a washing tank of theultrasonic-wave washer especially usable for dish washing.

In such an ultrasonic-wave washer, an ultrasonicwave is applied to awashing liquid in the tank through vibration of a vibrating board madeof a stainless steel etc. to which a plurality of tremblers are attachedfrom the back. In a conventional ultrasonic-wave washer of the type, anerosion which occurs on the vibrating board accompanying a strongultrasonic-wave generated in the liquid can be hardly prevented at thepresent technical level in this field. The erosion has a tendency togive a larger damage to the board, the stronger the vibration is.

Usually, the vibrating board is made of a 18-8 stainless steel foravoiding an erosion which, however, has sometimes a trouble ofbreakingthe tremblers during operation due to a difference incoefficients of thermal expansion between said 18-8 stainless steel anda ferrite forming the tremblers. Heretofore, in order to solve theproblem, a double coating of an aluminum plate over the under surface ofthe board or other measures have been adopted. It is most preferable toemploy a titanium for the double coating, which, however, is extremelyexpensive.

In analysis, the erosion on the vibrating board is found to be a kind ofevaporation of metals. When a metal hard to evaporate is applied to thesurface contacting the liquid, the advance of the erosion can be checkedto a considerable extent. Further, if the contact face is uniformly madeas smoothly as a mirrorface, adhesion of foams to the contact face canbe eliminated and a favorable contact with the liquid assuring a goodtransmission of the ultrasonic-wave can be obtained.

For further overcoming the erosion, there is an idea that the vibratingboard should be thick enough to withstand the erosion. In this case,however, thethicker the board is, the more deterioration of theultrasonicwave is observed. The stainless steel employed for thevibrating board has a large flexural rigidity in its property whichmakes it impossible to transmit a reliable vibration to the washingliquid when the vibrating board is made' thick enough to prevent theerosion. On the other hand, when the board is made thinner, thevibrating board easily yields to erosion.

It is, therefore, an object of the present invention to provide avibrating board for an ultrasonic-wave washer which is superior in itserosion resisting property and free from damages in tremblers, since thevibrating board has little difference in a coefficient of thermalexpansion from the tremblers made of a ferrite.

It is another object of the present invention to provide a vibratingboard for an ultrasonic-wave washer which can transmit a vibration ofthe vibrating board uniformly and effectively to a washing liquid andovercome a flexural rigidity of the board, even though employing a thickmaterial enough to withstand the erosion.

Essentially according to the present invention, there is provided avibrating board for an ultrasonic-wave washer fitted to an openingformed in the bottom of a washing tank and comprising a table portionprotruding in said tank and carrying a plurality of tremblersthereunder, a surface of said table portion contacting a washing liquidin said tank being plated with a hard chrome; and a flange portionintegrally formed with said table portion and fixed to the bottom of thetank.

Various, further, specific objects, features and advantages of thisinvention will be described by way of example with reference to theaccompanying drawings illustrating a preferred embodiment of thisinvention, in-- opening lb in its bottom 1a. A vibrating board 2 of 18-8stainless steel is attached to the washing tank from outside in such amanner that a table portion 2a of the vibrating board 2 protrudes insaid tank 1 through said opening 1b. Said vibrating board 2 is fixed tothe bottom la of the washing tank 1 by way of its flange portion 2b,through a packing member 3 provided therebetween, with bolts and nuts 4.

Tremblers 5 are fixed to the under surface of the table portion 2a ofthe vibrating board 2.

As shown in FIG. 2, the vibrating board 2 consists of a base plate 21 ofl88 stainless steel and a plated layer 22 of a hard chrome in thethickness of 20 30 t.

Further in order to overcome a trouble of erosion, the vibrating boardmay preferably be made of a thick material. However, as statedhereinbefore, the stainless steel employed for the vibrating board has alarge flexural rigidity in its property which makes it impossible totransmit a reliable vibration to the washing liquid, when the materialis made rather thick. This problem can be settled by making at least thefour corners of the table portion 2a and theflange portion 2b thinnerthan the central area of the table portion as illustrated in FIGS.

3 and 4. In this case, the four comers of the table 2a and the flangeportion 2b of the vibrating board 2 are planed thinner prior to pressingso as to be about onetion 2a is preferably 1.2 1.6 mm though it variesdepending on'the capacity of the washer and the number of the tremblers.Alternatively, the entire circumference of the table portion 2a exceptthe central area and the entire flange portion 2b may be formed thinner.

After planing is completed, a step is made in the vibrating board 2 toform the table portion 2a and the flange portion 2b in the process ofpressing.

The present vibrating board with at'least the four comers of the tableportion and the flange portion thereof planed thinner than the centralarea of the table portion 2a to which the tremblers 5 are attached canoffer a powerful sound field in the liquid in the washing tank and, atthe same time, can eliminate a breakdown by erosion, since thesubstantial portion of the board is formed thick. If two washing tankshaving the same capacity but provided with different vibrating board,namely, the conventional one and the present one are operated employingthe same ultrasonic-wave oscillator, the present vibrating board canproduce far stronger sound field than the conventional board. Therefore,in order to produce a determined sound field, the output power of theoscillator can be smaller in combination with the present vibratingboard advantageously from the economical point of view.

As set forth hereinabove, the vibrating board for an ultrasonic-wavewasher according to this invention has various advantages that theplating of a hard chrome over the surface thereof can highly elevate anerosion resisting property of 18-8 stainless steel and eliminate damagesin tremblers since a stainless steel plated with a hard chrome haslittle difference in a coefficient of thermal expansion from thetremblers made of a ferrite. Moreover, the surface of the vibratingboard is formed so smoothly with a hard chrome plating that a favorabletransmission of the ultrasonic-wave-can be assured.

Further advantages of the present invention are that span of life andthat, notwithstanding, the present vibrating board can offer a powerfulsound field in the tank with its thinner circumferential area.

. What is claimed is:

1. A vibrating board for an ultrasonic-wave washer fitted to an openingformed in the bottom of a washing tank and comprising a table portionprotruding in said tank and carrying a plurality of tremblersthereunder, a surface of said table portion contacting a washing liquidin said tank being plated with a hard chrome; and a flange portionintegrally formed with said table portion and fixed to the bottom of thetank.

2. A vibrating board for a ultrasonic-wave washer. as claimed in claim1, wherein the thickness of the finished plating layer of the hardchrome is about 20 30 u.

3. A vibrating board for an ultrasonic-wave washer as claimed in claim1, wherein at least four corners of the table portion and the flangeportion are formed thinner than a central area of the table portioncarrying the tremblers thereunder.

4. A vibrating board for an ultrasonic-washer as claimed in claim 3,wherein the thickness of the thinner area is about three-fourth of thatof the thicker area.

1. A vibrating board for an ultrasonic-wave washer fitted to an openingformed in the bottom of a washing tank and comprising a table portionprotruding in said tank and carrying a plurality of tremblersthereunder, a surface of said table portion contacting a washing liquidin said tank being plated with a hard chrome; and a flange portionintegrally formed with said table portion and fixed to the bottom of thetank.
 2. A vibrating board for a ultrasonic-wave washer as claimed inclaim 1, wherein the thickness of the finished plating layer of the hardchrome is about 20 - 30 Mu .
 3. A vibrating board for an ultrasonic-wavewasher as claimed in claim 1, wherein at least four corners of the tableportion and the flange portion are formed thinner than a central area ofthe table portion carrying the tremblers thereunder.
 4. A vibratingboard for an ultrasonic-washer as claimed in claim 3, wherein thethickness of the thinner area is about three-fourth of that of thethicker area.